Warm air

“ You know a great many times when you go out into the wind how cold it feels, and yet if the wind would actually stop, you would think it warm. It is the wind that causes the rapid evaporation and makes the surface of the skin feel cold. As it is true that the moisture in the air acts as a blanket to us in our homes, it is likewise as true that the vapor in its natural form outside of the house acts as a blanket for the earth. ”

“ The cooler air from the land is carried over the water by convection currents, flows in and under the warm air, is heated by the water and rises, to be replaced in turn by the further flow of cold air from the land. ”

“ Hot air goes up, so it is always warmer near the ceiling. You remember how warm air carries vapor up to make rain? It is the hot air that carries smoke up from chimneys. Did you ever send up a red paper balloon on the Fourth of July? You lit a tiny candle at the bottom. Soon the sides of the balloon swelled and stretched tight. Air expands when it is heated. That is, ittakes less hot air to fill anything than it does cold, so it grows lighter. ”

“ They are both made up of tiny particles of water.
“We have learnt that the streak of cloud left by the steam-engine melts away quickly on a hot day, also that the puff is farther from the funnel on a hot day. This shows us that the warmer the air is, the more water can it take up and hold. We have also learnt that warm air is light and rises up. [2]
“What happens when warm air, which holds much water-gas, rises up to the higher and colder parts of the sky?” ”

“ So, as the cooler air from above drops down, it acts like a mirror to the breath of the earth or the air that lies close over it; and this air is condensed into mist. All through the night both air and earth are cooling, but the earth more slowly, so that there is still a meeting of cooler and warmer air and consequent condensations, and the mist is hovering over the meadows when the next morning’s sun rises. As the sun mounts up, it begins to spread its warmth and the upper air is the first to feel it. Growing warm, it rises, drawing up after it the cooler air below. ”

“ Wind then by agitating the air should contribute to cool the earth and warm the atmosphere, by bringing a more rapid succession of fresh strata of air in contact with the earth, and yet in general wind feels cooler than still air? ”

“ In the morning the sun rose brilliant and quickly wore away the thin layer of ice that covered the water, and all the warm air was quivering with the steam that rose up from the quickened earth. ”

“ It is in winter, however, that the greatest care is required in providing a constant supply of pure air. If we would but accustom our minds to comprehend, readily and quickly, that cold air falls and warm air rises, it would assist us in our conclusions. ”

“ I answer, That doth not prove Air to be in its nature cold: for this moving or making of wind may contract or condense the air into cold motions, which may cause a cold wind, like as Ventiducts, where the air running thorow narrow Pipes makes a cold wind. The same may be done with a mans breath; for if he contract his lips close, his breath will be cold, but if he opens his mouth wide, his breath will be warm. ”

“ Suppose that the air which man breathes, instead of returning from his lungs clear and imperceptible to sight, were tinged with colour; we should see, that every time a man breathed, the air would rush in a stream into his mouth, and then return again; and the air which returned would, being warm, be lighter than the outer air, and would rise upward over the man's head, where, cooling and mingling with the outer air, it would descend again. ”

“ The hot day had warmed the air close to the pavement, but the cooling of the surface at the onset of darkness had caused a layer of warm air to be sandwiched in between the cold air close to the road surface and the cold air above. ”

“ The air contained inside of inhabited rooms gets warmed by the bodies and breaths of the persons living there. Then it is lighter, bulk for bulk, than the colder air outside, for warmth stretches and lightens everything. But as heavy things fall or press down to the earth more strongly than light ones, the cold air always squeezes into the room through the lower openings, and pushes the warm impure air out before it, through the upper ones. ”

“ For every portion of cool air, that approaches the warm skin, in receiving its part of that vapour, receives therewith a degree of heat, that rarifies and renders it lighter, when it will be pushed away, with its burthen, by cooler and therefore heavier fresh air ”

“ In the rays of the sun above the clouds he found it so warm as to cause him to perspire freely, a state of heat never before experienced at this hight, nearly twenty-four thousand feet, where the air is very rarefied and generally very chilly. ”

“ And thus, in a sudden change of the air from cold to warm, the instrument remaining longer cold may condense and absorb more moisture, and mark the air as having become more humid than it is in reality, and the contrary in a change from warm to cold. ”

“ As every Circumstance in the Order of Nature is so admirably contrived that each apparent Inconvenience rectifies itself; in heavy211 Winds continuing to blow from a cold Point; the Construction of the Atmosphere is such, that the warm light Air from the opposite Points will necessarily rise up and flow over the cold Stratum, and by their Tendency to an Equilibrium, will produce an Air less cold, before the same Wind is exhausted. ”

“ Because the clouds were grey with a load of rain and were running swiftly before an east wind the flesh became inattentive to the heat of the fire and participated in the chill of the open air, and though it is well to walk abroad on cold days, one wants to be warm when one sits by the hearth. ”

“ We, therefore, open the window and door in order to create a current of fresh air, and so allow the oxygen to be renewed. In this we but imitate nature, which sends a wind to purify the close atmosphere on warm summer days. ”

“ Let one person go out into the cold air in winter for a few minutes, and let another sit by a warm fire; then introduce both into a room without a fire: the person from the cold will feel it warm, and the other will feel it cold. ”

“ Wind is air that is in a hurry. You can feel it. Draw a quick breath. You felt a tiny wind in your nose, didn't you? You cannot feel air, but you can feel wind, or air in motion. You can feel the temperature of air, too. Your skin tells you if air is hot or cold. You can feel if it is damp or dry. You cannot smell air, but you can smell odors in it—the perfume of flowers, the freshness of rain, bad odors of decay, or smoke. You can train yourself to tell if the air in a room is fresh or stale. ”

“ After many frowns fortune has treated us to the kindest smile—for twenty-four hours we have had a calm with brilliant sunshine. Such weather in such a place comes nearer to satisfying my ideal of perfection than any condition that I have ever experienced. The warm glow of the sun with the keen invigorating cold of the air forms a combination which is inexpressibly health-giving and satisfying to me, whilst the golden light on this wonderful scene of mountain and ice satisfies every claim of scenic magnificence. ”

“ We do, in fact, see this action evidenced; when in winter time the cold condenses the vapour of the breath, we see the little cloud constantly rising before the breather's face, and dispersing in the surrounding air. ”

“ You ask me to explain why I am afraid of a draft of cool air; why I shiver more than others upon entering a cold room, and seem nauseated and repelled when the chill of evening creeps through the heat of a mild autumn day. ”

“ Warmer and sweeter grew the air; I could see the wall of rock on my right; and then I suddenly encountered a volume of air blown toward me, as if the sweetest perfumes of the earth were mingled in that breath of air. ”

“ But although my sense and reason inform me, that air in its own nature or essence is neither hot nor cold, yet it may become hot or cold, by hot or cold motions; for the sensitive perceptive motions of Air may pattern out heat or cold; and hence it is, that in Summer, when as heat predominates, the air is hot; and in Winter, when as cold predominates, the air is cold. But, perhaps, you will say, air may be cooled by moving it with a Fan, or such like thing which can make wind; wherefore it follows, that air must needs be naturally cold. ”

“ This morning sky, after the night's tempest, is a pure and dazzling blue. The air—the delicious air!—is full of sweet resinous odors, shed from the countless pine-boughs broken and strewn by the gale. ”

“ The air works for him. The atmosphere, a sharp solvent, drinks the essence and spirit of every solid on the globe,—a menstruum which melts the mountains into it. Air is matter subdued [130] by heat. As the sea is the grand receptacle of all rivers, so the air is the receptacle from which all things spring, and into which they all return. ”

“ When the decomposition of vapour, from the decline of the heat, is as yet but in commencement, or while the electricity remaining in the air continues to give buoyancy to the suspended particles, a delicious calm often prevails for many days in succession, amidst a perfect sunshine, mellowed by the vaporous air, and diffusing a rich golden tint, as the day declines, upon the landscape. ”

“ I see now as plain as day; the cold air settles down all round, like the iron box, and drives up the hot air as fast as the fire heats it, in the middle, like the water; and so the hot air carries the smoke along up with it, just as feathers and things in a whirlwind. ”

“ The air from B—"
"Do we begin all over again now?"
"More or less, yes."
"So that at this place, A, it's always raining or just going to rain?"
"Yes, if it starts by being hot there, as it did just now, I suppose it is."
"What happens if it starts by being cold?"
"It rains. I've explained that. The cold air can't contain so much moisture—"
"Don't begin that again. What about B? Is it any good going there? We had frightfully high pressure there at one time." ”

“ It comes from the breath of persons, and from the steam of the tea-kettle.
When the breath is blown on a cold object, like a piece of glass or metal, what is the result?
The moisture in the breath is condensed by the cold object, and is collected in small drops of water on its surface.
Frost. When the temperature of the air is reduced below thirty-two degrees, what becomes of the moisture collected on plants and other things? ”

“ There was not the least breath of wind to bring cooler air to the heated soil upon which we lay. Our lungs struggled to gulp down as much air as possible, and we could not bear to turn our eyes upon the glowing atmosphere. ”

“ After nightfall the air on mountain peaks and on hills and ridges soon becomes cooler than the air at the same elevation out over the open valley, due to contact with the elevated earth, which radiates heat and cools faster than the air. ”

“ The smoke, rising from several points at once, hangs in the air and collects into a dense canopy of cloud, making the heat still more stifling, till, at last, sheet-lightnings begin to play about it, followed by low growls of thunder, and, perhaps, by the blessed relief of a shower. ”

“ It is little more than a drift of the air brought into form by plumes; the air is in all its quills, it breathes through its whole frame and flesh, and glows with air in its flying, like blown flame; it rests upon the air, subdues it, surpasses it, outraces it,—is the air, conscious of itself, conquering itself, ruling itself. ”

“ In that community when the wind is south, the people fall ill; when it is northwest, it sets them coughing; with a north wind they do indeed recover but cannot stand about in the alleys and streets, owing to the severe cold.
2. Wind is a flowing wave of air, moving hither and thither in­definitely. It is produced when heat meets moisture, the rush of heat generating a mighty current of air. That this is the fact we may learn from bronze eolipiles, and thus by means of a scientific invention discover a divine truth lurking in the laws of the heav­ens. ”

“ Q. Why does wind in England generally feel cold?
A. Because a constantly changing surface comes in contact with our body, to draw off its heat.
Q. Why is a room (even without a fire) generally warmer than the open air?
A. As the air in a room is not subject to much change, it soon becomes of the same temperature as our skin, and no longer feels cold.
Q. Why do we generally feel colder out-of-doors?
A. Because the air (which surrounds us) is always changing; and as fast as one portion of air has become warmer by contact with our body, another colder portion surrounds us to absorb more heat. ”

“ Both land and water are heated by the sun’s rays, and the same change in the air then takes place which we find also at our firesides. The layer of air next the warmed earth becomes itself warmed. As it thereby grows lighter it ascends, and its place is taken by colder air, which flows in from the neighborhood to take its place. This flowing in of air is wind.
One of the most important ingredients in the air is the vapor of water. ”

“ When there has been a hot sunshiny day, and when the ground has been wet, the sun attracts a great deal of vapour: then that vapour must have room, so it must push away some air to make room for itself; besides, vapour swells with heat, so it must have a great, great deal of room as it grows hotter, and hotter; and the moving the air to make way for it, must make wind. ”

“ I say, some sorts: and certainly, the strongest Winds are made of the grossest Vapours. As for Smoak, it is apt to turn into some sorts of Lightning; I say, apt: for, both Vapour and Smoak can turn into many sorts of Metamorphosed Elements. As for Wind, it proceeds either from Rarified Vapour, or Contracted Air. And there are many sorts of Vapours, Smoaks, and Winds; all which sorts of Vapours and Smoaks, are apt to ascend: but, Wind is of a more level action. As for Clouds, they cannot be composed of a Natural Air; because Natural Air is too rare a Body to make Clouds. ”